Breast cancer is a leading cause of death for women in the United States, and an estimated 43,300 women will die of breast cancer in 1999. As tumors grow, an extensive vasculature is formed. Recent measurements have shown a clear correlation between high local blood flow and the existence of breast tumors. This project proposes the innovative use of an optical imaging technique for real-time perfusion monitoring of breast tissues. Detection of changes in the vascular structure of breasts using optical methods offers a means for regular, noninvasive, and sac monitoring of patients and for early detection of tumors. The hypothesis of this research is that the proposed technique can be used to identity regions of high cutaneous blood flow due to increased vascularity associated with malignant breast tumors. The objective is to establish the feasibility of the technique for breast cancer detection. Specific aims of Phase I include developing a prototype, evaluating the prototype, establishing baselines and accuracy of the method, and investigating critical engineering milestones for Phase II. PROPOSED COMMERCIAL APPLICATIONS: The proposed technique will provide a useful tool for breast tumor screening. The optical imaging device is economical and portable and can be used by primary care physicians and gynecologists. The component cost of a commercial device is estimated to be less than $1,200. This device can be used with mammography and may reduce the requirements for repeated x-ray exposures.